The project title for the studies begun 1974-1975, and continued during the present year, should be retitled simply Mechanism of State Dependent Learning, since it better reflects the expanded thrust of the efforts in this area. This research has incorporated a large variety of methods of manipulating state (pharmacological, clinically-related behavioral, and combinations of these) but has also deliberately attempted to integrate and bridge the areas of animal learning, human learning, psychopharmacology and clinical investigation.